The Cold War was a time of great tension between the the west and the east, with the USA, the UK and their allies pitted against the Soviet Union and its satellite states in Eastern Europe. Germany, divided after World War II, was particularly important as the place where the two sides came face to face. During the early 1960s the tension escalated with the nuclear arms race, proxy wars, propaganda and espionage, the Cuban missile crisis and the construction of the Berlin Wall, that most visible symbol of the Cold War.